1. Field of the Invention
The present invention relates to a machine tool including: a first and a second spindle headstock disposed on a bed; and a tool post disposed between the first and second spindle headstocks.
2. Description of the Related Art
An example of a machine tool of this type is structured such that, when seen from a front side of the machine, a first spindle headstock is fixedly disposed on a left end portion of a bed, a second spindle headstock is disposed on a right side to be movable in a Z-axis direction, and an upper tool post and a lower tool post are disposed between the first and second spindle headstocks to be movable in the Z-axis direction and an X-axis direction (see, for example, FIG. 4 of Patent document 1). In this machine tool, a workpiece having been subjected to predetermined machining by the first spindle headstock is transferred and attached to the second spindle headstock by a workpiece delivery device, and is subjected to the other machining by the second spindle headstock.
[Patent document 1] Japanese Patent Application Laid-open No. 2001-87901
Incidentally, the aforesaid conventional machine tool requires the workpiece delivery device, which poses a problem that cost of the machine accordingly increases.
In order to eliminate the need for the workpiece delivery device, it is necessary for the second spindle headstock to move up to a workpiece delivery position of the first spindle headstock for direct delivery of the workpiece. In this case, a tool post is disposed at a position where it does not interfere with the second spindle headstock, for example, on a front side when seen from the front side of the machine. However, disposing the tool post at the position not causing the interference gives rise to a problem that the front/back direction dimension of the machine main body accordingly increases.